Skin cancer is the most common form of cancer in the United States. The two most common types are basal cell carcinoma and squamous cell carcinoma (the names come from the type of cells in which the cancer begins). They usually form on the head, face, neck, hands, and arms. Another type of skin cancer, melanoma, is less common than the others, but far more dangerous — even deadly. It involves the cells that produce the skin pigment melanin, which is responsible for skin and hair color. Melanoma can spread very rapidly, and the incidence of melanoma in the United States is steadily increasing. It is the leading cause of death from skin disease.
The development of melanoma is related to sun exposure, particularly to sunburns during childhood. It is most common among people with fair skin, blue or green eyes, and red or blond hair.
Screening and Diagnosis
Melanoma may appear on normal skin, or it may begin in a mole or other area that has changed in appearance. Some moles present at birth may develop into melanomas. The primary symptom of any skin cancer is usually a mole, sore, lump, or growth on the skin. Any change in appearance of a pigmented skin growth over time is a warning sign. Also, watch for any bleeding from a skin growth.
The ABCD system may help you remember features that might be symptoms of melanoma:
- Asymmetry: One half of the abnormal area is different from the other half.
- Borders: The lesion or growth has irregular edges.
- Color: Color changes from one area to another, with shades of tan, brown, or black (sometimes white, red, or blue). A mixture of colors may appear within one growth.
- Diameter: The trouble spot is usually (but not always) larger than 6 mm in diameter — about the size of a pencil eraser.
The key to treating melanoma is recognizing symptoms early. You might not notice a small spot of concern if you don't look carefully, so perform thorough self-examinations on a regular basis.
To treat melanoma, the cancerous skin cells and a portion of the normal surrounding skin usually have to be surgically removed. You may need a procedure called surgical lymph node biopsy to check if the cancer has spread to nearby lymph nodes. If it has, these lymph nodes may also need to be removed. A skin graft may be necessary after the surgery if a large area of skin is affected.
Only the smallest and most shallow melanomas can be cured by surgery alone, so early diagnosis is very important. Radiation therapy, chemotherapy, or immunotherapy (use of medications that stimulate the immune system, such as interferon) may be recommended in addition to surgery. If the skin cancer is deeper than 4mm or the lymph nodes have cancer, there is a high risk of the cancer spreading to other tissues and organs. After surgery, treatment with interferon, a class of drugs that helps your immune system fight off the cancer, may be useful for these patients.